他是来自M78星云的光之巨人，为了追捕逃亡的宇宙怪兽百慕拉而来到地球。在龙森湖上空追击百慕拉时，他不慎与科学特别搜查队队员早田进所乘的战斗机相撞，导致早田坠机死亡。为了弥补自己的过失、以及挽救早田进的生命，奥特曼将自己的生命给予了早田，与之一心同体使其复活。之后，奥特曼与早田一起，为保卫地球而与众多凶暴的怪兽和邪恶的宇宙人展开了激烈的战斗。

Ultraman is a Japanese tokusatsu science fiction television series produced by Tsuburaya Productions. It is a follow-up to Ultra Q, though not technically a sequel or spin-off. Tsuburaya Productions produced 39 episodes (40, counting the pre-premiere special) that aired on Tokyo Broadcasting System (TBS) and its affiliate stations from July 17, 1966, to April 9, 1967. Its premiere topped the average rating set by Ultra Q and kept climbing each week, marking the show as a success.